1. Technical Field
Embodiments described herein are related to the field of integrated circuits, and more particularly to calibrating clock signals between integrated circuits.
2. Description of the Related Art
Computing systems may include one or more systems-on-a-chip (SoCs), which may integrate a number of different functions, such as, application execution, graphics processing and audio processing, onto a single integrated circuit (IC). With numerous functions included in a single IC, chip count may be kept low in mobile computing systems, such as tablets, for example, which may result in reduced assembly costs, and a smaller form factor for such mobile computing systems.
Various computing systems may include multiple SoCs or other types of ICs. Some of these computing systems may include ICs in more than one voltage domain, i.e., different ICs powered by different power supplies which may have different power supply voltage levels and/or different common mode voltage levels (also commonly referred to as “ground reference,” “voltage grounds,” or simply “grounds”). In some systems, a clock signal in an SoC in one voltage domain may be calibrated to a different clock signal in an IC in another voltage domain. Distributing a single clock signal across multiple voltage domains may result in level shifting circuits being used to cross voltage domains, which may introduce delay and complexity into the design.